1. Field of the Invention
The present invention generally relates to telecommunication networks and, more specifically, it pertains to methods for communication resource management in such networks. More particularly, the present invention relates to a method and system for the common management of communication resources in telecommunication networks having several (at least two) distinct communication resources pools.
2. Description of the Related Art
In radio communication networks, Radio Resource Management (RRM) methods are performed during normal system operation within network apparatuses that manage and control the radio resources of the cells included in a radio telecommunications network.
Among RRM methods, Common Radio Resource Management (CRRM) methods take into account the possibility of jointly managing radio resources in a “heterogeneous” cellular radio mobile network.
A heterogeneous cellular network includes different radio access technologies and is generally of the “multiple-access” type, meaning that the part of the network providing access to the network transport segment is implemented by two or more systems conforming to different standards.
Several radio mobile cellular system standards already exist nowadays. The so-called “second generation” or “2G” systems, like for instance the GSM system, and “third generation” or 3G systems, including e.g. the UMTS, which are still the most broadly diffused, will be increasingly operated in combination with newly deployed systems, in particular designed to offer wide-band access, such as for example E-UTRAN (Evolved UMTS Terrestrial Radio Access Network), WiMAX and future IMT-Advanced (International Mobile Telecommunication) systems (still on their way of definition).
Second-generation cellular networks are mostly adapted to provide voice services, while third-generation and fourth-generation networks are intended to support, in addition to voice services, a wide variety of new data and multimedia services. It is generally expected that, at least for some years, the newly deployed cellular networks will not completely substitute the existing, second- and third-generation networks. They will rather integrate existing networks by offering to customers the possibility of using new types of services in addition to the standard voice service. Integration is made possible by the characteristics of the new standards, which have been defined in such a way as to permit operation in a joint and synergic manner with existing cellular networks, and to offer a wide variety of services to user owning multi-mode terminals (cellular phones, palmtops, Personal Digital Assistants—PDAs—, network interface cards for Personal Computers—PCs, and similar devices).
A heterogeneous network is a network including, for instance, both the radio access segment of a GSM (General System for Mobile communications) system and the radio access segment of a UMTS (Universal Mobile Telecommunication System) system, as well as, possibly, additional radio access segments of different standards.
Some of the CRRM solutions known in the art operate in such a way that users are moved from one radio access system to another when the service is already being provided. Methods of this type are for example disclosed in US2005/90257, U.S. Pat. No. 6,944,144, U.S. Pat. No. 6,963,745, WO 2000/35226 and WO 2003/069938.
Other solutions have been proposed which start acting at the service request. Most of the solutions of this type however are limited to the transfer of users from a system to another only when the currently used system is close to congestion; these CRRM algorithms are “congestion-prevention” oriented.
As a general solution known in the art, EP 1519607 discloses a method and system for performing radio resource management in a mobile radio network based on exchanging load information among different network entities (CN, RNC/BSC, Node B/BTS, CRRM server) in a mobile radio network. The solution is characterized in that user equipment information and/or subscriber related information and/or radio cell status information from different network entities are transmitted to a Common Radio Resource Management entity; said pieces of information are used in said Common Radio Resource Management entity for deciding on the most suitable network access.
A further solution is disclosed in CA 2593314 that describes in a multi-access system, an access selection principle achieved by selecting a signal strength threshold level based on a determined load level in a first access network. A new user in an area commonly covered by more than one access network attempts to allocate to the first access network if an experienced signal strength exceeds the signal strength threshold level. Communication utility can preferably be maximised or at least be taken into account by using suitable load level dependencies. By increasing the threshold when the load level approaches the capacity limit, a completely filled first access network is avoided. This gives an opportunity to let particularly well-suited users still have access to the first access network. At the same time, since the preferred access is decided before the actual access attempt, control signalling can be significantly reduced, even at very high traffic loads.
WO 2005/101880, in the name of the present Applicant, discloses a method for providing, in a communication network including at least a first (e.g. GSM) and a second (e.g. UMTS) set of resources, a service to users of at least a first and a second type. The users of the first type are in a condition to be provided said service only by said first set of resources, while the users of said second type are in a condition to be provided said service both by said first set of resources and by said second set of resources. The method includes the steps of: detecting during at least one time interval, the total number of requests for service coming from said users, identifying within the total number the fraction of requests adapted to be met only by said first set of resources, identifying at least one parameter representative of said fraction, and providing the service to said users of said second type by said second set of resources as a function of said at least one parameter.